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Potentially life-threatening emergency
Necrotizing fasciitis - Cellulitis
See also in: Overview,External and Internal Eye
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Potentially life-threatening emergency

Necrotizing fasciitis - Cellulitis

See also in: Overview,External and Internal Eye
Print Images (3)
Contributors: Tara Mahar MD, Art Papier MD
Other Resources UpToDate PubMed

Synopsis

Necrotizing fasciitis is a deep and often devastating bacterial infection that tracks along fascial planes and expands well beyond any outward cutaneous signs of infection (ie, erythema). It may be classified as polymicrobial (type I) or monomicrobial (type II). It occurs from the extension of infection at the site of a skin lesion such as an abrasion, furuncle, or insect bite in 80% of cases. Classically, group A beta-hemolytic streptococci (Streptococcus pyogenes) are associated with necrotizing fasciitis, but many other organisms including Staphylococcus aureus, Vibrio vulnificus, Enterobacteriaceae, and Bacteroides spp. have been reported. Polymicrobial infection is frequent. Group A Streptococcus and S. aureus, in particular, should be considered in necrotizing fasciitis resulting after a varicella infection.

Aeromonas hydrophilia is part of the Vibrionaceae family and can cause necrotizing fasciitis in both immunocompromised and immunocompetent patients. Unlike V. vulnificus sepsis, where exposure is usually to seawater, in A. hydrophilia infection, contact with brackish water, soil, wood, or dirty ditches is typically the common exposure. Infections can follow any trauma, fracture, or injury where there was exposure to fresh water. Infection has also occurred in the setting of debris or floodwater after a hurricane. Both V. vulnificus and Aeromonas infections can present with lower leg hemorrhagic bullae, purpura, and skin necrosis. A. hydrophilia infection, in contrast to infection with V. vulnificus, is marked by more myonecrosis and a distinctive foul odor when the wound is debrided. Most patients with A. hydrophilia had exposure to wet soil or dirty ditches.

Patients with necrotizing fasciitis are acutely ill. They are often thought to have cellulitis that is not responding to standard antibiotic therapy. Pain is out of proportion to physical findings. There is often associated skin necrosis and bullae formation. Signs of systemic illness such as fever, lethargy, hypotension, and tachycardia are present; these may progress to multi-organ failure. Predisposing factors for necrotizing fasciitis include recent surgery, diabetes mellitus, malignancy, and alcohol use disorder.

The mortality of necrotizing fasciitis is high. Treatment includes broad-spectrum intravenous antibiotics and immediate surgical debridement of infected and devitalized tissue. Therefore, if you are considering this diagnosis, stop reading this and contact a surgeon now.

Codes

ICD10CM:
M72.6 – Necrotizing fasciitis

SNOMEDCT:
52486002 – Necrotizing fasciitis

Look For

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

It can sometimes be difficult to differentiate necrotizing fasciitis from pyoderma gangrenosum (PG). This is especially true in the pustular variant of PG that may not develop into frank ulceration. Relatively rapidly progressing soft tissue inflammation not responding to broad-spectrum antibiotics and surgical debridement should be promptly evaluated by a dermatologist to rule out PG.

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Best Tests

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Management Pearls

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Therapy

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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References

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Last Updated: 06/08/2018
Copyright © 2018 VisualDx®. All rights reserved.
Potentially life-threatening emergency
Necrotizing fasciitis - Cellulitis
See also in: Overview,External and Internal Eye
Print 3 Images
View all Images (3)
(with subscription)
Necrotizing fasciitis : Fever, Erythema, Pain out of proportion to exam findings, Painful skin lesions
Clinical image of Necrotizing fasciitis
Copyright © 2018 VisualDx®. All rights reserved.